Promise.js

async function getGameId(){
  // Create a 6 figure game code.
  let idSize = 2;
  let id = Math.floor(Math.random() * Math.pow(10, idSize)).toString();
  id = id.padStart(idSize, '0');

  // See if that game already exists  
  let snapshot = await db.collection("games").doc(id).get()
  if (snapshot.exists) {
    console.log("Game " + id + " already exists");
    return getGameId();
  }

  return id;
}

// Create a game, setting the owner as the current player
function createGame(player_id){

  return getGameId().then(id => {
    // The below creates a new promise.
    // How can I make createGame() return this promise?
    return db.collection("games").doc(id).set({owner: player_id});
  });
}


createGame(req.body.player_id).then((game) => {
  console.log("complete!");
});